The present invention relates in general to a solid-state image sensing device and, more particularly, to a color CCD image sensor which is swing-driven to periodically shift position relative to incident image light.
In order to obtain color image signals using one solid-state image sensor such as the charge-coupled device (CCD), there has been a well-known technique of employing an assembly of optical mosaic patterned color filters which have a wavelength transmission characteristic suitable for CCD's twodimensional picture element arrangement. In the case of a color filter arrangement according to the frequency interleaving system suitable for CCD's field storage mode, for example, cyan filter components, whole transmission filter components and yellow filter components are alternately arranged in an appropriate manner. In the case where one frame image consists of two field images according to the NTSC system, for example, and when signal reading is suitably done from the color filter components in each of the fields, three primary color signals, that is, red (R), green (G) and blue (B) signals, which are necessary for a color signal process can be obtained by adding, and/or subtracting output image signals of the color filter components by means of one scanning line delay memory.
When the frequency band of G signal components is made wide to enhance the image resolution of the color CCD image sensor of this type, false signal (or moire, for example) are caused in the reproduced image which degrade its image quality. The overlap between the band for the G signal components and the band for the modulating signal components, which use CCD's sampling frequency fc (or fc/2) as their carrier frequency, increases, when the band for G signal components is made wider, thereby causing the undesirable moire phenomenon the (bad influence caused by the overlap of these signals is most prominent in the vicinity of fc/2). It is commonly considered that the CCD's sampling frequency fc may be set high to prevent the occurrence of moire. Setting the sampling frequency high, however, means an increase in the number of CCD's picture elements, and such an increase is difficult since it will lower productivity using current manufacturing facilities.